False twist apparatus such as twist tubes have long been known in connecting with the processing of filamentary materials. See for example, U.S. Pat. No. 4,115,986 (the entire disclosure of which is incorporated herein by reference), which describes a revolving tube for producing a so called false twist in a device for texturing textile yarns. In this case the yarn passes through the revolving tube in its longitudinal direction, although is guided around a mandrel disposed approximately in the center of the tube. As the tube is made to revolve, the yarn is twisted. In order to thread-in or introduce the yarn before texturing, it must be introduced into an axial hole at one end face of the revolving tube, looped once around the mandrel and guided out again.
The known revolving bodies of this kind may well be suitable for continuous processes, but they present a disadvantage in cases where yarn processing operations of short duration are concerned. In such cases too much time is taken up by threading one end of the yarn into the revolving tube. Although it would be possible to eliminate this disadvantage by means of an automatic threading device, this ultimately results in a very expensive solution to the problem.